KR20200024766A - Vacuum valve with position sensor - Google Patents

Abstract

The present invention relates to a vacuum valve (1) with a valve stop (4) and with a drive unit (7) having at least one adjustment element (5) and coupled to the valve stop (4). The vacuum valve 1 is in the zero position, in particular the position of the valve plug 4 with respect to the open position O or the closed position G of the vacuum valve 1 and / or the position of the at least one adjustment element 5. It further has a position sensor 10, 10 ′, in particular a movement or distance sensor so that can be measured.

Description

Vacuum valve with position sensor

The present invention relates to a vacuum valve having at least one position sensor and a method for controlling a vacuum valve using position measurement.

Vacuum valves for regulating the volume or mass flow of flow paths leading through openings formed in the valve housing and / or for essentially gas-tight closure are generally known from the prior art in various embodiments and in particular contaminated particles. It is used in vacuum chamber systems in IC, semiconductor or substrate production areas, where it must be done in a protected atmosphere without the need to. Such a vacuum chamber system is particularly provided for receiving a semiconductor element or substrate to be processed or produced, through which at least one vacuum chamber opening has at least one vacuum chamber opening through which the semiconductor element or other substrate can be guided into and out of the vacuum chamber. An evacuable vacuum chamber and at least one vacuum pump for evacuating the vacuum chamber. For example, in a production plant for a semiconductor wafer or liquid crystal substrate, the high sensitivity semiconductor or liquid crystal element sequentially passes through several process vacuum chambers in which components located within the process vacuum chamber are each processed by the processing device. During the machining process in the process vacuum chamber and during the transfer from the chamber to the chamber, the high sensitivity semiconductor element or substrate should always be in a protected atmosphere—especially in an air free environment.

To this end, peripheral valves are used to open and close gas inlets or outlets, and transfer valves are used to open and close the transfer openings of the vacuum chamber for inserting and removing parts.

The vacuum valve through which the semiconductor component passes is called a vacuum transfer valve, mainly a rectangular valve due to a rectangular opening cross section and also a slide valve, rectangular slider or transfer slide valve due to the application area and the associated dimensions described.

Peripheral valves are used, in particular, to control or regulate the gas flow between the vacuum chamber and the vacuum pump or other vacuum chamber. For example, a peripheral valve is located in the pipe system between the process vacuum chamber or transfer chamber and the vacuum pump, atmosphere or other process vacuum chamber. The opening cross section of such a valve, also known as a pump valve, is generally smaller than the opening cross section of a vacuum transfer valve. Peripheral valves are also called control valves because they are used not only to fully open and close the opening, but also to control or regulate the flow by continuously adjusting the opening cross section between the fully open position and the gas-tight closed position. . Possible peripheral valves for controlling or regulating gas flow are pendulum valves.

In a typical pendulum valve, as known from US 6,089,537 (Olmsted), the first step typically involves rotating the round valve plate from a position to release the opening, from an open position to an intermediate position covering the opening, usually through the round opening. will be. In the case of a slide valve, as described, for example, in US 6,416,037 (Geiser) or US 6,056,266 (Blecha), the opening, as well as the valve plate, is typically rectangular and removes the opening from a position that releases the opening in this first step. It is pushed linearly to the covering intermediate position. In this intermediate position, the valve plate of the pendulum or slide valve is positioned at a distance from and opposite the valve seat surrounding the opening. In the second step, the distance between the valve plate and the valve seat is reduced such that the valve plate and the valve seat are evenly pressed against each other so that the valve cap is reached in the closed position and the opening is essentially gas-tightly closed. This second movement preferably occurs in a direction substantially perpendicular to the valve seat.

Each end position of the adjustment movement, ie the open position and the closed position (and an adjustment position, provided also an intermediate position if provided with two combined partial movements in at least two different adjustment directions, is also provided) is detected and / or The case is maintained using a mechanical end position switch. Narrow tolerance limits must be kept unfavorable for this purpose for correct closure.

The sealing is via a sealing ring arranged on the plug side of the valve plate pressed onto the valve seat surrounding the opening, or via a sealing ring on the valve seat against which the plug side of the valve plate is pressed. May occur. Due to the closing procedure occurring in two stages, the sealing ring between the valve plate and the valve seat breaks the sealing ring, since in the second stage the movement of the valve plate occurs essentially linearly and vertically on the valve seat. It receives little shear force.

Various prior art sealing devices are known, for example, from US Pat. No. 6,629,682 B2 (Duelli). Suitable materials for sealing rings and seals in vacuum valves are, for example, fluoro rubbers, also known as FKM, in particular fluoroelastomers known under the trade name "Viton" and perfluoro rubber, abbreviated FFKM.

From the prior art, different drive systems are available, for example from US 6,089,537 (Olmsted) for pendulum valves and US 6,416,037 (Geiser) for slide valves, valves of slide valves parallel to the rotational movement and opening of the valve plate of the pendulum valve. It is known to achieve translational movement of the plate and substantially translational movement perpendicular to the opening.

The valve plate must be pressed against the valve seat in such a way that damage to the sealing medium, in particular the sealing ring in the form of an O-ring, is avoided, which ensures the required gas tightness within the entire pressure range and is caused by excessive pressure loading. . To ensure this, known valves provide pressure regulation of the valve plate which is adjusted according to the pressure difference present between the two valve plate sides. Particularly in the case of large pressure fluctuations or changes from partial vacuum to overpressure or vice versa, a uniform force distribution cannot always be ensured along the entire circumference of the sealing ring. In general, the aim is to uncouple the sealing ring from the bearing force due to the pressure exerted on the valve. For example, in US Pat. No. 6,629,682 (Duelli), a vacuum valve with a sealing medium is proposed, which consists of a sealing ring and a support ring adjacent to it, so that the sealing ring is essentially supportive.

Perhaps some known pendulum valves or slide valves may be displaced perpendicularly to the valve plate in addition to or alternatively to the second moving step and enclose the valve plate to achieve the gas tightness necessary for both overpressure and partial vacuum. And pressurized onto the valve ring to close the valve in a gas-tight manner. Such valves having a valve ring that can be actively displaced with respect to the valve plate are known for example from DE 1 264 191 B1, DE 34 47 008 C2, US 3,145,969 (von Zweck) and DE 77 31 993 U. US 5,577,707 (Brida) describes a pendulum valve having a valve housing having an opening and a valve plate swiveling parallel across the opening to control the flow through the opening. The valve ring surrounding the opening can be actively moved vertically in the direction of the valve plate by several springs and compressed air cylinders. Possible further development of such a pendulum valve is proposed in US 2005/0067603 A1 (Lucas et al.).

Since the aforementioned valves are used above all for the production of high-sensitivity semiconductor elements in the vacuum chamber, the corresponding sealing effect for this process chamber must also be reliably ensured. For this purpose, in particular the state of the sealing surface in contact with the sealing material or the sealing material during compression is particularly important. During the service life of the vacuum valve, wear of the sealing material or the sealing surface can typically occur.

Further, for example due to the appearance of wear or aging, or due to external interference effects such as mechanical shocks, the drive system and / or mechanically moving components of the valve are vulnerable to defects, thus generally sealing the vacuum valve. Impairment of function or functionality or reliability may occur. To date, there has been no option in the prior art to recognize such defects early and / or in advance.

Thus, in order to maintain the quality of the valves and / or seals consistently at a sufficiently high level, maintenance of the valves is typically made by frequently replacing or restoring parts of the valves, for example seals, drive parts or the entire valve. At specific time intervals. Such maintenance cycles in this case are typically sized based on the number of open and closed cycles expected in a particular period of time. Thus, maintenance is usually done as a preventive measure to make it possible to prevent the occurrence of leaks or other failures in advance.

This maintenance requirement is not limited to sealing material or valve plate, but extends to, for example, a valve seat that forms part of a vacuum valve corresponding to the valve plate. The structure of the sealing surface on the valve seat side, for example a groove embedded in the valve seat, is also affected by mechanical stress. Thus, structural changes in the grooves due to valve operation can also damage the seal. Appropriate maintenance intervals are also typically defined for this purpose.

The disadvantage of such valve maintenance is its preventive nature. Parts affected by maintenance are typically renewed or replaced before their regular or actual life expires, which means increased costs. Each such maintenance step typically means a certain downtime and increased technical and financial effort for the production process. In short, this means stopping production at intervals that are shorter than necessary and more frequent than may be needed.

Accordingly, the present invention is based on the object of providing an improved vacuum valve that allows for optimal operation.

It is a further object of the present invention to provide an improved vacuum valve which allows for optimized valve maintenance and thus improves, ie shortens possible process stops.

It is a further object of the present invention to provide an improved vacuum valve which can extend the service life of individual valve parts.

It is a further object of the present invention to provide an improved vacuum valve which places less stringent tolerance requirements for the individual components and / or for production.

These objects are solved by the realization of the characteristic features of the independent claims. Further developments of the invention in an alternative or advantageous manner can be found in the dependent patent claims.

The basic idea of the invention is to equip the vacuum valve with a position sensor and to design the valve and sensor arrangement in such a way that it is possible to preferably determine or monitor the position of at least one mechanically moved part of the valve.

Accordingly, the subject of the present invention is a vacuum valve, preferably a vacuum slide valve, a pendulum valve or a mono valve, for the regulation of volume or mass flow and / or gas-tight shutoff of the flow path, which defines the opening axis. And a valve seat having an opening and a first sealing surface surrounding the valve opening. The valve seat may in this case be an essential component or a structural component of the vacuum valve and in particular implement part of the valve housing. Alternatively, the valve seat may be formed by an opening in a process chamber, for example a vacuum chamber, and may cooperate with a valve stopper that is movable in relation to the valve seat to form a vacuum valve in the sense of the present invention.

The vacuum valve also comprises a valve stopper, in particular a valve plate, for regulating volume or mass flow and / or for blocking the flow path, the valve stopper having a second sealing surface corresponding to the first sealing surface. The variable position is determined by the respective position and alignment of the valve stopper. In addition, the vacuum valve has a drive unit coupled to the valve stopper, the drive unit comprising at least one movable adjustment element, for example an adjustment arm, wherein the drive unit is designed to carry out an adjustment movement. The valve closure is such that there is an axial sealing contact with respect to the opening axis from the open position where the valve stopper and the valve seat are provided without contacting each other between the first sealing surface and the second sealing surface, in particular through the seal. It is thereby possible to adjust the valve opening to a closed position in which the valve opening is closed in a gas-tight manner and again in reverse.

In particular, one or both of the two sealing surfaces have a seal made of sealing material. The sealing material can be, for example, a polymer-based material (eg, an elastomer, in particular a fluoroelastomer), which is vulcanized on the sealing surface or provided as an O-ring in the groove of the valve plug or valve seat. do. Thus, the sealing surface is considered in the scope of the present invention to be a surface in which a seal, preferably made of a sealing material, is provided in compressed form to close the valve opening (closed position).

The drive unit can be designed as an electric motor (stepper motor) or in combination of a plurality of motors or as a pneumatic driver. In particular, the drive unit provides for movement of the valve stopper in at least two directions (essentially orthogonal to each other).

According to the invention, the vacuum valve has at least one position sensor, wherein the position sensor is in the position of the valve plug and / or at least one adjustment element, in particular the adjustment arm, relative to a null position, in particular an open position or a closed position. Is preferably designed and arranged in a vacuum valve so that it can be measured gradually.

The position sensor is preferably a displacement sensor that includes a position-conversion element. Alternatively, the sensor is designed as a distance sensor. In the case of a plurality of sensors, both types can also be used. Since the position sensor is preferably designed as an absolute position sensor, the position can be determined without approaching the null position, for example by the unique position code on the ruler, the material measurement or the scale of the sensor.

The sensor is preferably designed and arranged in the vacuum valve so that the time curve of at least part of the adjustment movement can be determined. Thus, a plurality of positions are determined sequentially over a particular time range such that, for example, at least one speed of the adjustment movement or the adjustment element and / or the valve stopper can be determined therefrom during at least one such time range of the adjustment movement. Or can be derived. In addition, acceleration can also be further determined from the position measurement.

Optionally, the adjustment movement comprises at least essential linear movement, and the position sensor is designed and arranged to obtain at least part or all of the linear movement, wherein the position sensor is preferably a linear encoder.

Alternatively or additionally, the adjustment movement comprises at least essentially rotation movement, wherein the position sensor is designed and arranged to obtain at least part or all of the rotation movement, wherein the position sensor is preferably an angular encoder.

The position sensor is optionally an inductive, optical, magnetic, magnetostrictive, potential difference and / or capacitive position sensor. As an additional option, the position sensor is arranged outside the vacuum region, which is defined by the vacuum valve and is separated from the external environment. Thus, in this case it is advantageous for the sensor arrangement to be designed such that, for example, the sensor itself does not need to be moved to the vacuum region, so that relatively less construction costs can be ensured.

In some embodiments, the position sensor is designed and arranged in a vacuum valve such that the position measurement can be performed with respect to at least two adjustment directions which are essentially orthogonal to one another by one position sensor, ie a single position sensor The position can be determined with respect to the axis or direction of. This means that, for example, the target of the sensor is sequentially, for example, first in the adjustment along the first adjustment direction and then in the adjustment along the second adjustment direction, or simultaneously, for example as a 2D position sensor. By design it is received from a plurality of rulers. Alternatively, the vacuum valve has at least two position sensors, in which the position with respect to the first adjustment direction in the vacuum valve can be measured by the first position sensor and the position with respect to the second adjustment direction to the second position sensor. It is designed and arranged so that it can be measured, in particular where both adjustment directions are essentially orthogonal to one another.

In one embodiment, the vacuum valve has a monitoring and control unit for operating the drive unit using predefined control values to adjust the valve stopper between the open and closed positions, where the drive unit, valve stopper and sensor Is designed and interacts so that the control value is set based on the measurement signal of the sensor, in particular the measurement signal continues to correspond to a predefined set value.

In this case, the vacuum valve, the sensor arrangement and the monitoring and control unit may be configured such that, for example, the sensor is in one or two way communication via a conventional wired or wireless connection with the monitoring and control unit, for example for the preparation and transmission of a specific signal. Optionally configured.

The vacuum valve is also designed, for example, in particular so that the acquired measurement signal provided by the monitoring and control unit or sensor arrangement can be processed by the processing unit and an item of status information can be generated based on the obtained measurement signal. May have a processing unit. The acquired measurement signal can then be further processed and provided for provision as user information or an item of status information that can be evaluated, for example, for valve adjustment by the monitoring and control unit.

The item of state information is for example based on the actual-set point comparison to the acquired position measurement signal, for example on the basis of the position acquired and expected relative to the reference (set) position of the drive unit, for example. For example, an item of information may be provided in relation to the mechanical and / or structural integrity of the valve closure and / or the adjustment element.

Further, based on the item of state information, an output signal may be provided that specifies the relationship of the acquired position sensor measurement signal to a specific tolerance value. Thus, in particular, an evaluation can be made regarding the process controlled by the vacuum valve, for example whether the required sealing action is achieved or whether for example possible damage to the adjusting element or the sealing surface can be recognized. have. For example, whether the process is running within the required tolerances (eg, based on the adjustment speed or the termination position) or whether an unwanted drop or excess below this tolerance is expected, for example a visual or acoustic signal Can be displayed to the user.

The invention also includes a method for controlling a vacuum valve, in particular a vacuum slide valve, a pendulum valve or a mono valve, the vacuum valve being designed for regulating volume or mass flow and / or gas-tight shutoff of the flow path. . The controlled vacuum valve is in this case a valve cap having a valve opening defining an opening axis and a first sealing surface surrounding the valve opening, for adjusting the volume or mass flow and / or for shutting off the flow path. A valve closure, at least one movable adjustment element, in particular a valve plate, having a second sealing surface corresponding to the first sealing surface, the variable position being determined by the respective position and alignment of the valve stopper. And a drive unit coupled to the valve stopper, wherein the drive unit is designed to perform an adjustment movement such that the valve stopper is provided with respect to the opening axis from an open position provided without contacting the valve stopper and the valve seat with respect to each other. An axial sealing contact is present between the first sealing surface and the second sealing surface, in particular through the seal, so that the valve opening is It is possible in the closed position are closed in such a way, and contrary adjustment.

According to the invention, in the scope of the invention, the particularly absolute position of the valve plug and / or at least one adjustment element relative to the null position, in particular the open position or the closed position, is measured in particular.

In one refinement of the method, in the scope of the method, in particular with regard to the mechanical and / or structural integrity of the valve stopper or valve element, an item of status information of the vacuum valve is identified on the basis of the position measurement and preferably the status The item of information is identified by a real-set point comparison to the acquired measurement signal and / or based on a comparison of the item of status information to a predefined tolerance value, so that the output signal is controlled by the vacuum valve. It is provided in connection with the evaluation.

The adjustment speed of the valve plug and / or the at least one adjustment element is based on the position measurement for at least a portion of the adjustment movement and / or the interval of the adjustment movement from the open position to the closed position and / or vice versa in the scope of the method. Is optionally determined. This item of information can in this case be output to the user in the form of a diagram for analysis and / or analyzed automatically.

As a further option, the possible impact of the sealing surfaces against each other in the range of detection and / or adjustment movement of the valve plug and / or the end position of the at least one adjustment element, in particular the open position and / or the closed position, and / or each other Possible adhesion of the sealing surface to is made in the scope of the present method based on the position measurement.

The subject matter of the invention also relates to a program code for carrying out the method according to the invention, which is stored in a machine-readable carrier, in particular a control and processing unit of a vacuum valve according to the invention, or a computer data signal implemented by electromagnetic waves. Having a computer program product.

Accordingly, the present invention advantageously provides a vacuum valve that allows for continuous or continuous position measurement of the valve plug and / or the adjustment element so that the adjustment movement or sequence can be monitored or checked and possibly evaluated. In addition, the position measurement enables automatic and continuous status verification of the individual of the vacuum valve and / or its components, for example of the drive unit, of the seal or of the adjustment element, where the item of status information is a moving part. Not only can be directly identified or derived through, but can also be indirectly identified or derived through fixed components. In this case, defects or irregularities representing future defects can only be recognized early or all and / or a lack of defects is established so that unnecessary maintenance can be avoided. The check can in this case be advantageous during the normal process sequence, so it does not need to be interrupted.

The vacuum valve according to the invention is explained in more detail below by means of an embodiment schematically shown in the drawings. Like elements are designated by like reference numerals in the drawings. In principle, the described embodiments are not to scale and should not be understood as limiting.

The drawings show the following in detail:
1a and 1b show a first possible embodiment of a vacuum valve according to the invention as a monovalve.
2 shows a second possible embodiment of a vacuum valve according to the invention as a mono valve.
3 shows a possible further embodiment of the vacuum valve according to the invention as a transfer valve.
4a and 4b show a schematic view of a further embodiment according to the invention of a vacuum valve as a pendulum valve.
5 shows a schematic view of a further embodiment according to the invention of a vacuum valve as a transfer valve.
6 shows a schematic view of a further embodiment according to the invention of a vacuum valve as a transfer valve.

1a and 1b schematically show a first embodiment of a vacuum valve 1 according to the invention. In this example, the valve 1 is implemented as a so-called mono valve and is shown in cross section in the open position O (FIG. 1A) and in the closed position G (FIG. 1B).

The valve 1 for gas-tight closure of the flow path by linear movement has a valve housing 24 comprising an opening 2 for the flow path, where the opening 2 has a geometric opening axis H along the flow path. Has The opening 2 connects the first gas region L and / or the partition (not shown) located on the left side of the valve 1 in the figure with the second gas region R on the right side thereof. Such partitions are formed, for example, by the chamber walls of the vacuum chamber.

The closure element 4 is from the open position O which releases the opening 2 in the closing direction and again in the opening direction by the drive unit 7 with the movable positioning element 5 in the exemplary adjusting arm. It is possible to displace linearly along the geometry adjustment axis V extending transversely to the opening axis H in the plug element plane 22 in the closed position G which is pushed linearly over the opening 2.

For example, the curved first sealing surface 3 is along the first section 21a in the first plane 20a and along the second section 21b in the second plane 20b. Surrounds the opening (2) of. The first plane 20a and the second plane 20b are spaced apart from each other, extend parallel to each other, and extend parallel to the plug element plane 22. The first section 21a and the opposing second section 21b thus have geometric offsets transverse to the adjustment axis V with respect to each other and in the direction of the opening axis H. The opening 2 is arranged between two opposing sections 21a, 21b in the region extending along the adjustment axis V. FIG.

The closure element 4 has a second sealing surface 6 which extends along the section corresponding to the first and second sections 21a, 21b and which corresponds to the first sealing surface 3.

Mono valves, ie vacuum valves which can be closed by a single linear movement, for example have the advantage of a relatively simple closing mechanism, for example over a transfer valve which can be closed by two movements requiring a relatively complex configured actuator. Have The closure element can also be formed in one piece, so that it can be subjected to high acceleration forces, and this valve can also be used for quick and urgent closure. Closing and sealing can be accomplished by a single linear movement, which allows very fast closing and opening of the valve 1.

In particular, one advantage of the monovalve is that the seals 3, 6 are not subjected to transverse loads in relation to the longitudinal extension of the seals 3, 6, for example because of the profile during closing. The seals 3, 6, on the other hand, have a plug element due to the lateral extension to the opening axis H, in particular in the case of large differential pressures which require a firm configuration of the plug element 4, its driver and its mount. It is hardly possible to absorb the force generated on the closure element 4 along the opening axis H which may act on (4).

According to the invention, the vacuum valve 1 shown in FIGS. 1A and 1B has in this example a position-transforming element (target) 8 and a sensor surface 9 (ruler) for its detection. A displacement sensor 10. The displacement sensor 10 is for example a (non-contact) inductive displacement sensor, for example a differential transformer with a displaceable core, a pulse inductive linear position sensor, a PLCD displacement sensor (permanent linear non-contact displacement sensor), an optoelectronic displacement sensor, It is designed as a potential difference displacement sensor, magnetostrictive displacement sensor, capacitive displacement sensor or magnetic displacement sensor. According to the sensor 10, the ruler 9 is active and the position-translating element 8 is passive or vice versa, ie the (electrical or electronic) measurement signal and / or analytical signal is the ruler 9 or element ( By 8) or tapping respectively.

In this example, the target 8 is fixed on or inside the adjustment element 4, and thus moves along it along the adjustment axis V. The sensor surface 9 extends in the adjusting direction V at least over the entire adjusting distance, so that the position of the target 8 and thus the adjusting element 4 is measured over the possible total linear movement of the adjusting element 4. It is possible. In this case, the position is identified in relation to the starting position or the null position, which is preferably either the open position O or the closed position G. The displacement sensor 10 is preferably an absolute encoder in this case. Alternatively, incremental displacement sensors are used.

Thus, the actual position of the adjustment element 4 can advantageously be determined by the position sensor 10. In this case the position measurement can be limited to the determination of one or several positions, preferably for example the end position (ie the open position O and / or the closed position G) in the sense of the end position detection. However, since continuous or continuous positioning is preferably made, the position of the adjusting element 4 is known gradually, in particular a time curve.

By means of the sensor arrangement according to the invention, for example, the closing capability of the valve can be checked accordingly during the process sequence, the contact pressure can be adjusted accordingly, and a leak-tight failure can be predicted possibly. . In particular, for example, the compression can be set individually using the electric drive unit 7. Using the pneumatic actuator 7 it can be checked at least using the sensor arrangement whether the valve is closed.

Knowledge of the chronological movement curve is optionally used to determine the speed of linear movement of the plug element 4 therefrom. This can advantageously be used for improved end position determination, whereby the tolerance of the vacuum valve becomes less important. Thus, the correct interval for the closing or opening procedure can also be identified, thereby enabling, for example, optimization or defect recognition. In general, the analysis of the time-displacement curve, for example performed by an external data processing system to which the position sensor 10 and / or the vacuum valve 1 are connected, allows for inference about the state of the valve 1. do. Thus, irregularities or changes in the course of the operating cycle can be recognized and thus can conclude the state of the moving component or the sealing surfaces 3, 6, for example. For example, when the two sealing surfaces 3, 6 are bonded to each other in the closed position G, the position of the adjusting element 4 remains constant for a certain length of time due to the adhesive force, so that the rapid opening movement and A short kickback is subsequently driven by the drive unit 7 via the adjustment element 5, but can therefore be recognized in the movement sequence.

2 shows an alternative of the embodiment according to FIGS. 1 a and 1b. In this example, the vacuum valve 1 has a position sensor 10 designed as a distance sensor. The distance sensor 10 is, for example, an optoelectronic distance sensor or an ultrasonic sensor and corresponds to the measuring signal 13, for example by means of an emitter in the direction of the adjustment element 4 and / or the vertical axis V. It emits laser light, so that the signal 13 is incident on the adjustment element 4 (back face in this example), reflected at least in part from it, and received again by the detector of the sensor 10. In this case, the distance between the sensor 10 and the adjustment element 4 and thus the position of the adjustment element 4 is determined by the determination of the signal runtime (pulse runtime method) and / or phase difference measurement, phase or frequency runtime method, And / or in accordance with the Fizeau principle. As a further option, the positioning is made by triangulation.

In order to improve the distance and / or position measurement, in this example, the vacuum valve 1 has a reflector 14 arranged on the adjustment element, which reflects the measurement signal 13 towards the sensor 10 and receives it. It is designed to improve the signal level of the measured measurement signal 13.

Alternatively to the arrangement shown, the sensor 10 is arranged on a moving part, ie here on the stopper 4, and emits measurement radiation 13 towards the static point of the valve 1 (ie , Array inverted from the drawing).

3 shows a further embodiment of the vacuum valve 1 according to the invention, designed as a transfer valve in this example, shown in a different plug position.

The illustrated transfer valve is a special type of slide valve. The vacuum valve has a rectangular plate closure element 4 (eg a valve plate), which has a sealing surface 6 for gas-tight closure of the opening 2. The opening 2 has a cross section corresponding to the closure element 4 and is formed in the wall 12. The opening 2 is surrounded by a valve seat, which in turn provides a sealing surface 3 which also corresponds to the sealing surface 6 of the closure element 4. The sealing surface 6 of the closure element 4 surrounds the closure element 4 and has a sealing material (seal). In the closed position, the sealing surfaces 6, 3 are pressed against each other and the sealing material is compressed at the same time.

The opening 2 connects the first gas region L located on the left side of the wall 12 and the second gas region R on the right side of the wall 12. The wall 12 is formed by, for example, the chamber wall of the vacuum chamber. The vacuum valve 1 is then formed by the interaction of the chamber wall 12 with the closure element 4.

The closure element 4 is arranged here, for example, on an adjustment arm 5 which is rod-shaped and extends along the geometric adjustment axis V. The adjusting arm 5 is mechanically coupled to the drive unit 7, whereby the closing element 4 is opened via the intermediate position Z (FIG. 3 (b)) in the open position O (FIG. 3). in the first gas region L on the left side of the wall 12 by adjusting the adjustment arm 5 by the drive unit 7 between (a)) and the closed position G (FIG. 3C). It is adjustable.

In the open position O, the closure element 4 is located outside the projection area of the opening 2 and completely releases it, as shown in Fig. 3A.

By adjusting the adjustment arm 5 in the axial direction parallel to the first, " vertical " adjustment axis V and parallel to the wall 12, the closure element 4 is moved from the open position O to the intermediate position Z. It can be adjusted by the furnace drive unit 7.

In this intermediate position Z (FIG. 3B), the sealing surface 6 of the closure element 4 overlaps the opening 2 and the sealing surface of the valve seat surrounding the opening 2. It is located at a position spaced apart from (3).

The adjustment arm 5 is adjusted in the direction of the second "horizontal" adjustment axis H (transverse to the first adjustment axis V), ie perpendicular to the wall 12 and the valve seat, for example. By doing so, the closure element 4 can be adjusted from the intermediate position Z to the closed position G (FIG. 3C).

In the closed position G, the closure element 4 closes the opening 2 in a gas-tight manner and separates the first gas region L from the second gas region R in a gas-tight manner.

Thus, opening and closing of the vacuum valve are made by the drive unit 7 by L-shaped movement of the closure element 4 and the adjustment arm 5 in two directions H, V perpendicular to each other. Thus, the illustrated transfer valve is also referred to as an L-type valve.

The transfer valve 1 as shown is typically provided for sealing the process volume (vacuum chamber) and for loading and unloading the volume. For such use a frequent change between the open position O and the closed position G is common. Thus, the appearance of increased wear of the sealing surfaces 6, 3 and mechanically moved components, for example the adjusting arm 5 or other parts of the drive unit 7, may occur.

In order to prematurely determine the appearance of such wear, the vacuum valve 1 according to the invention first of all has a position sensor 10 designed in the example as a two-axis displacement sensor. In contrast to the embodiment according to the example of FIGS. 1A and 1B, the position is determined in both adjustment directions V, H by the target 8 attached to the adjustment element 5. To this end, the vacuum valve 1 has a first "vertical" ruler 9v and an intermediate position Z and a closed position () for positioning of the "vertical" movement between the open position O and the intermediate position Z. It has a second "horizontal" ruler 9h for positioning of the "horizontal" movement between G). By the target element 8 arranged on the adjusting element 5 and the first ruler 9v, the sequential movement sequence is in the open position O-the intermediate position Z-the closed position G (or vice versa). In the sequential sequence accordingly, the position of the adjustment element 5 is thus measured in the first "vertical" adjustment direction V and, by the target 8 and the second ruler 9h, the position is adjusted to the second "horizontal". Measured in the adjustment direction (H).

In this example, the valve 1 and / or the position sensor 10 further have a control and / or analysis unit 11, whereby the position measurement is controlled and / or the position data is recorded or analyzed, For example, an external computer can be omitted (substantially), for example, valve-internal monitoring or condition monitoring of the valve 1 is done alone.

Alternatively to the two sequentially arranged linear rulers 9v and 9h shown, a single 2D sensor surface is used (not shown), which is for example optically scanned and thus both axes or directions (V and Simultaneous determination of the position of the adjustment element 5 to H) becomes possible.

As a further alternative, the positioning for two adjustment directions (V, H) or two adjustment movements is not made by a single position sensor 10, but rather the valve 1 has a respective adjustment direction (V, H). Or one position sensor 10 for adjustment movement, and thus includes two position sensors 10.

4a and 4b schematically show a further possible embodiment of the valve according to the invention in the form of a pendulum valve 1. The valve 1 for the essentially gas-tight shutoff of the flow passage has a valve housing with an opening 2. The opening 2 here has, for example, a circular cross section. The opening 2 is surrounded by the valve seat. This valve seat is formed by a (first) sealing surface 3 which extends axially in the direction of the valve plate 4 and transversely to the opening axis H, has the shape of a circular ring and has a valve housing. Is formed. The valve plate 4 is pivotable about the rotational axis R and is adjustable substantially parallel to the opening axis H. In the closed position G (FIG. 4B) of the valve plate 4 (valve plug), the opening 2 is gas-tightly closed by the valve plate 4 with the second sealing surface 6. The open position O of the valve plate 4 is shown in FIG. 4A.

The valve plate 4 is connected to the drive unit 7 via an arm 5 arranged transversely on the plate and extending perpendicular to the opening axis H. This arm 5 is located in the closed position G of the valve plate 4 outside the opening cross section of the opening 2 which is geometrically projected along the opening axis H. As shown in FIG.

The driver 7 is designed by the use of a motor and corresponding gearing so that a valve plate 4 conventional in a pendulum valve is essentially parallel to the opening axis H transversely and across the cross section of the opening 2. And pivot by transverse movement x of the driver 7 in the form of pivot movement Br around the pivot axis R between the open position O and the intermediate position perpendicular to the opening axis H. It is possible to displace linearly by the longitudinal movement Bv of the driver 7 which occurs parallel to the opening axis 5. In the open position O, the valve plate 4 is located in a dwell section arranged laterally adjacent to the opening 2, so that the opening 2 and the flow path are released. In the intermediate position, the valve plate 4 is spaced apart above the opening 2 and covers the opening cross section of the opening 2. In the closed position, the opening 2 is gas-tightly closed and there is a gas-tight contact between the sealing surface 6 of the valve cap 4 (valve plate) and the sealing surface 3 of the valve seat. At this point the flow path is blocked.

In order to enable automated and controlled opening and closing of the valve 1, the valve 1 provides, for example, an electronic regulation and control unit (not shown), which allows the valve plate 4 to It is designed to be adjustable accordingly for the gas-tight termination or for the regulation of the internal pressure of this volume and connected to the driver 7.

In the present exemplary embodiment, the driver 7 is designed as an electric motor, where the gearing is switchable such that the drive of the driver 78 causes either lateral movement (Br) or longitudinal movement (Bv). . The driver including gearing is electronically activated by the regulator. Such gearings, in particular with slotted link shift units, are known from the prior art. It is also possible to use a plurality of drivers to cause rotational movements Br and linear movements Bv, where the controller assumes activation of the drivers.

The precise adjustment and / or setting of the flow rate using the described pendulum valve 1 is not only possible by the pivoting of the valve plate 4 between the open position O and the intermediate position by lateral movement Br, First of all it is possible by linear adjustment of the valve plate 4 along the opening axis H and / or R between the intermediate position and the closed position by the longitudinal movement Bv. The pendulum valve described can be used for precise adjustment operations.

The valve plate 4 and also the valve seat both have a sealing surface-first and second sealing surfaces 3, 6, respectively. The first sealing surface 3 also has a seal 23. Such a seal 23 can be vulcanized, for example, as a polymer by vulcanization on a valve seat. Alternatively, the seal 23 can be embodied, for example, as an O-ring in the groove of the valve seat. The sealing material may also be adhesively bonded on the valve seat to implement the seal 23. In an alternative embodiment, the seal 23 can be arranged on the side of the valve plate 4, in particular on the second sealing surface 6. Combinations of these embodiments can also be considered. This seal 23 is, of course, not limited to the valve 1 described in the example, but may also be applied to the valve embodiment described further.

The valve plate 4 is variably set based on, for example, an adjustment variable and an output control signal. For example, an item of information on the current pressure state in the process volume connected to the valve 1 is received as an input signal. In addition, additional input variables, for example mass inflow into the volume, may be provided to the regulator. Based on these variables and based on the predefined setpoint pressures that must be set or achieved for the volume, the regulated setting of the valve 1 is made over the regulation cycle time, so that large discharges from the volume It can be adjusted over time by 1). For this purpose, a vacuum pump is provided behind the valve 1, ie the valve 1 is arranged between the process chamber and the pump. Thus the desired pressure curve can be modulated.

Each opening cross section with respect to the valve opening 2 is set by the setting of the valve cap 4, so that the amount of gas that can be discharged per unit time from the process volume is set. The valve stopper 4 may have a shape deviating from the circle for this purpose, in particular to achieve the most possible laminar flow of media.

In order to set the opening cross section, the valve plate 4 is driven by the transverse movement Br of the driver 7 from the open position O to the intermediate position and the longitudinal direction of the driver 7 from the intermediate position to the closed position. It is adjustable by the adjustment and control unit by the movement Bv. In order to fully open the flow path, the valve plate 4 is driven by the longitudinal movement Bv of the driver 7 from the closed position G to the intermediate position and therefrom the driver 7 from the intermediate position to the open position O. Can be adjusted by the controller by the rotational movement (Br).

Pressurization of the valve seat 4 on the valve seat ensures that the required gas-tightness is ensured within the entire pressure range and the valve 1 or more accurately the sealing surfaces 3, 6 or seals due to excessively large pressure deformation. Damage to the (s) 23 should be made to be avoided. To ensure this, the known valve plate provides a contact pressure regulation of the regulated valve plate 4 as a function of the pressure difference present between the two valve plate sides.

According to the invention, the valve 1 has two position sensors 10 and 10 'designed in the example as a linear encoder 10 and an angular encoder 10'.

The linear position sensor 10 extends on the arm 5 along the linear direction of movement Bv on the arm 5 and thus stops the valve 1, for example in relation to the valve housing of the drive unit 7. It has a scale 9 which is movable in the feeding direction Bv with respect to the part. Each relative position is identified by a linear encoder by the read head 8, which reads the scale 9 with a position code for this purpose. The scale 9 and / or read head are in this case at least partially formed “wide” so that the linear position can also be measured at different rotational positions of the arm 5. Thus, the scale 9 extends for example far enough around the arm 5, part of which is opposed to the detector 8 in both the open position O and also in the closed position G, the scale 9 Cannot be pivoted out of the “field of view” of the detector 8.

The location code is preferably an absolute location code. Alternatively, the location code is an incremental code. In absolute position sensors 10, 10 ′, the position has an absolute position code consisting of code words that are unique over the entire measurement distance by which the scale 9 can be associated with exactly one position by the control and analysis unit. In this respect, it can be directly associated with all relative positions of the read head 8 relative to the scale 9 (associated with the previously defined null position). In contrast, in position encoders 10 and 10 'with incremental determination of position, the scanning signal is not unique but rather repeated multiple times over the entire measurement range. The distance that the increment corresponds to is stored in the control and analysis unit of the encoder. Thus, the distance covered during the relative movement of the scale 9 and the read head 8 can be saved, and the relative position can be determined by counting the increments. To position this relative position in an absolute manner, in the case of relative movement, it proceeds from the null position defined as an absolute reference point. This null position or null point is defined, for example, by a positional reference marker detected by the read head 8 on the scale 9 (or on the read head 8 in the case of a fixed scale 9). . Sensors 10, 10 ′ with incremental determination of the translation position or angle therewith have the disadvantage that they must proceed from the null or reference position at each time in the event of a restart of the measuring system. In contrast, an absolute linear or angular encoder produces a unique differentiateable scanning signal for each relative position of a part that can be translated or rotated relative to each other. The unique linear position and / or unique angle can thus be associated with each relative position directly, ie without approaching the reference or starting position.

The second position sensor 10 'designed as an angular encoder also has a scale 9' with absolute or incremental angular coding, which is scanned by the read head 8 ', so that the arm 5 and thus the valve plate The item of information on the angular position of (4) can be obtained. In this example, the scale 9 'extends at least partially around the arm 5 (at least enough to cover the circumference of the rotational movement Br by it), and thus the fixed detector 8' or the valve 1 Rotatable with the arm (5) with respect to the entire fixed part of.

By means of the first and second position sensors 10, 10 ′, the movable part of the valve 1, in particular the position of the valve plate 4, in particular the gas-tightness and / or the gas-tight closing function are required. The condition of the vacuum valve 1 in terms of reliability can be advantageously monitored and evaluated accordingly in a continuous manner.

As an alternative to the illustrated pendulum valve 1, the vacuum valve 1 according to the invention uses a different vacuum valve type, for example a flap valve, a slide valve or a so-called butterfly control valve. Can be implemented. Pendulum valves can also be used, the closure of which can only be adjusted in one direction.

5 schematically shows a further possible position sensor arrangement in the transfer valve according to the invention, as shown in the closed position G (FIG. 5 (a)) and the open position O (FIG. 5 (b)). Represented by In the figure shown, the valve seat 3 is formed on the housing 24 of the vacuum valve 1. However, it will be apparent to those skilled in the art that the following description may apply essentially similarly to the embodiments, wherein the valve seat is provided by a process chamber, ie a chamber housing.

It is also clear here that the valve mechanism, which is only schematically shown as a tilt mechanism, should not be understood to be limiting, and a person skilled in the art may, for example, take a sensor arrangement according to the invention in a similar manner. It can be switched to any L-motion driver, for example the L-motion driver has two linear adjustment directions of the valve plate perpendicular to each other.

For the monitored guidance of the adjustment arm 5, the vacuum valve 1 here has, for example, a guide component 15, where the drive unit 7 and the guide component 15 are here for example. The drive unit 7 and also the guiding component 15 are each in a fixed arrangement with respect to each other in that they are each connected in place to the valve housing 24. The adjustment arm 5 is also mechanically coupled to the valve stopper 4 and the drive unit 7, whereby by adjusting the valve arm 5 by the drive unit 7, the valve stopper 4 has a valve seat. Essentially parallel to, in particular in L-motion movement, as described in FIG. 3, adjustable between the open position (O) and the closed position (G).

According to the invention, the guide component has a position sensor 10. In this case the position sensor 10 is designed such that both the "vertical" component V and also its "horizontal" component H of the movement of the arm 5 and / or the valve plate 4 can be measured. The position sensor 10 has a rotary encoder for this purpose, for example the tilt position of the arm 5 (ie the "horizontal" component) and also its linear in that the rotary encoder is previously converted to rotational movement. Used to determine both translations. Alternatively to the figures, two separate position sensors are used and / or position sensors or sensors are arranged at different points of the valve, for example on the driver 7.

6 shows a further possible embodiment of the vacuum valve 1 according to the invention, similar to FIG. 5. In contrast to the embodiment according to FIG. 5, the position sensor 10 for measuring the position of the valve plug 4 and / or the adjustment element 5 is here an illumination means 16, for example an adjustment arm 5. It is designed as a system with an LED for illuminating the rear end of s) and a camera system 17 for obtaining the illumination radiation reflected from the adjusting arm 5. The camera system 17 has a position-sensitive detector, for example, so that the position of the adjustment arm 5 can conclude from the radiation reflected from the incident position onto the detector. Alternatively, for example, generation and image analysis of the image with the obtained radiation may be performed, from which position can be determined. Camera-based positioning is known in principle from the prior art. It is also known to use optically obtainable patterns to improve imaging positioning. Thus, as shown, the rear end of the adjustment element 5 has this optical pattern 18. The "horizontal" position of the adjustment element 5 can be concluded from the position of the pattern 18 in the camera image, the "vertical" position (distance to the camera) of the image pattern (in comparison with the stored reference variable) It can be concluded from or part of the imaged size.

It is thus evident that the figures shown are merely schematic illustrations of possible exemplary embodiments. Various approaches can be combined with each other and with prior art methods and devices.

Claims (15)

As the vacuum valve 1, in particular
As a vacuum slide valve, pendulum valve or monovalve for the regulation of volume or mass flow and / or gas-tight shutoff of the flow path,
A valve seat having a valve opening (2) defining an opening axis (H) and a first sealing surface (3) surrounding the valve opening (2),
A valve closure (4), in particular a valve plate, for regulating the volume or mass flow and / or for shutoff of the flow path, the second sealing surface (6) corresponding to the first sealing surface (3) Wherein the variable position of the second sealing surface 6 is determined by the respective position and alignment of the valve closure 4,
A drive unit 7 coupled to the valve stopper 4, comprising at least one movable adjustment element 5, wherein the drive stopper 7 is provided with a valve stopper 4.
o from the open position O in which the valve cap 4 and the valve seat are provided without contacting each other.
o An axial sealing contact with respect to the opening axis H is present between the first sealing surface 3 and the second sealing surface 6, in particular via a seal 23, whereby the valve A drive unit, which is designed to carry out the adjustment movements Bv, Bh, Br so that the opening 2 is adjustable in the closed position G, which is closed in a gas-tight manner, and vice versa,
The vacuum valve 1 further comprises at least one position sensor 10, 10 ′, wherein the position sensor 10, 10 ′ is in particular in a continuous manner with the valve cap 4 and / or the at least one The position of the adjustment element 5 is designed and arranged in the vacuum valve 1 so that it can be measured with respect to the null position O, G, in particular the open position O or the closed position G. Vacuum valve (1). The method of claim 1,
The position sensor 10, 10 ′ is such that the time curve of at least a portion of the adjustment movements Bv, Bh, Br can be determined, in particular at least one speed of the adjustment movements Bv, Bh, Br is adjusted. Vacuum valve (1), characterized in that it is designed and arranged in the vacuum valve (1) so that it can be determined for at least one time range of movement (Bv, Bh, Br). The method according to claim 1 or 2,
Vacuum valve (1), characterized in that the position sensor (10, 10 ') is designed as a displacement sensor or distance sensor and / or an absolute position sensor (10, 10'). The method according to any one of claims 1 to 3,
The adjustment movements Bv, Bh, Br comprise at least essentially linear adjustment movements Bv, Bh and the position sensor 10 is designed to obtain at least a portion of the linear adjustment movements Bv, Bh. Vacuum valve (1), characterized in that the position sensor (10) is a linear encoder. The method according to any one of claims 1 to 4,
The adjustment movements Bv, Bh, Br at least essentially comprise a rotation adjustment movement Br, the position sensor 10 'is designed and arranged to obtain at least a portion of the rotation adjustment movement Br, In particular, the position sensor (10 ′) is an angle encoder, vacuum valve (1). The method according to any one of claims 1 to 5,
The position sensors 10, 10 ',
Inductive, optical, magnetic, magnetostrictive, potential difference and / or capacitive position sensors 10, 10 ', and / or
Vacuum valve (1), characterized in that arranged in a prescribed manner outside the vacuum range separated from the external environment by the vacuum valve (1). The method according to any one of claims 1 to 6,
The position sensor 10, 10 ′ is configured such that the position measurement by means of the one position sensor 10, 10 ′ can be performed in particular with respect to at least two adjustment directions which are essentially orthogonal to one another with respect to one another. Designed and arranged in the valve 1,
The vacuum valve 1 can be measured by a first position sensor 10, 10 ′ in a position with respect to a first adjustment direction, and a position with a second position sensor 10, 10 ′ with a second position in the second adjustment direction. Have at least two position sensors 10, 10 ′ designed and arranged in the vacuum valve 1 so that they can be measured by), in particular both adjustment directions are essentially orthogonal to one another and / or
The valve seat is formed by a part of the vacuum valve structurally connected to the vacuum valve 1, in particular the valve seat being formed on a housing 24 of the vacuum valve 1 or in a process chamber, in particular Vacuum valve (1), characterized in that provided by the chamber housing. The method according to any one of claims 1 to 7,
The vacuum valve 1 is designed such that the acquired position sensor measurement signal can be processed by the processing unit 11 and the item of status information of the vacuum valve 1 is identified based on the obtained measurement signal. Vacuum valve (1), characterized in that it has a processing unit (11). The method of claim 8,
The item of status information is provided in relation to the mechanical and / or structural integrity of the valve stopper 4 and / or the adjustment unit 5, in particular the item of status information is based on the actual- Vacuum valve (1), characterized in that it is confirmed by a set point comparison. The method according to claim 8 or 9,
Based on the comparison of the item of state information to predefined tolerance values, an output signal is provided in connection with the evaluation of the process controlled by the vacuum valve (1). As a method for controlling a vacuum valve 1, in particular a vacuum slide valve, a pendulum valve or a monovalve, the vacuum valve 1 is designed for the regulation of volume or mass flow and / or for gas-tight shutoff of the flow path, The vacuum valve 1,
A valve seat having a valve opening 2 defining an opening axis H and a first sealing surface 3 surrounding the valve opening 2,
A valve stopper 4, in particular a valve plate, for regulating the volume or mass flow and / or for blocking the flow path, having a second sealing surface 6 corresponding to the first sealing surface 3. The valve stopper, wherein the variable position of the second sealing surface 6 is determined by the respective position and alignment of the valve stopper 4,
A drive unit 7 coupled to the valve stopper 4, comprising at least one movable adjustment element 5, which drive unit 7 executes adjustment movements Bv, Bh, Br. Is designed so that the valve stopper 4
o from the open position O in which the valve cap 4 and the valve seat are provided without contacting each other.
o An axial sealing contact with respect to the opening axis H is present between the first sealing surface 3 and the second sealing surface 6, in particular via a seal 23, whereby the valve A drive unit, which can be adjusted to the closed position G, in which the opening 2 is closed in a gas-tight manner, and vice versa,
In the scope of the method, in a particularly continuous manner, in particular the absolute position of the valve plug 4 and / or the at least one adjustment element 5 is in the null position O, G, in particular in the open position O or in the closed position. Method, characterized in that it is measured relative to position (G). The method of claim 11,
In the scope of the method, in particular with regard to the mechanical and / or structural integrity of the valve stopper 4 or the adjustment element 5, an item of status information of the vacuum valve 1 is identified based on the position measurement. Especially
The item of status information is identified by a real-set point comparison to the obtained measurement signal and / or
The output signal is provided in relation to the evaluation of the process controlled by the vacuum valve (1), based on a comparison of the item of state information to predefined tolerance values. The method of claim 11 or 12,
In the scope of the method, based on the position measurement,
The speed of adjustment of the valve stopper 4 and / or the at least one adjustment element 5 is determined for at least a portion of the adjustment movement Bv, Bh, Br, and / or
The interval of said adjustment movement (Bv, Bh, Br) from said open position (O) to said closed position (G) and / or vice versa is determined. The method according to any one of claims 11 to 13,
In the scope of the method, based on the position measurement,
The end position of the valve stopper 4 and / or the at least one adjustment element 5, in particular the open position O and / or the closed position G and / or
Possible impact of the sealing surfaces 3, 6 against each other in the range of the adjustment movement Bv, Bh, Br and / or
The detection of possible adhesion of the sealing surfaces (3, 6) to each other is carried out. With a machine-readable carrier, in particular a control and processing unit of the vacuum valve 1 according to claim 1, or a program code for carrying out the method according to claim 11, which is stored in a computer data signal implemented by electromagnetic waves. Computer programs.

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